**Abstract**

The number of studies on insecticides, which constitute an important class of pesticides, is increasing day by day. These chemicals used in the fight against pests in the field of agriculture; It is also used to fight mosquitoes and insects in homes, gardens and rural areas. Excessive use of insecticides has adversely affected many beneficial organisms besides target organisms. As a result of the negative effects of insecticides on non-target organisms, the normal balance of nature has been disturbed and this has led to the decline of some living species in the world. In many studies from the past to the present, it has been shown that these insecticides have negative effects on the environment, human and animal health. Some of these chemicals, which have many benefits in the fight against agricultural pests, have been banned due to their harmful effects on non-target organisms as a result of excessive use. Today, however, these chemicals are still used intensively against agricultural pests, threatening non-target organisms and human health. For this reason, in this book chapter we have prepared, the negative effects of insecticides on living things are examined by reviewing biochemical and histopathological studies.

**Keywords:** Pesticide, insecticide, oxidative stress parameters, histopathology changes

## **1. Introduction**

The rapid and uncontrolled increase in the world population brings along the need for nutrition and food. Today, the failure to provide agricultural products at the level to meet the increase in world population causes problems of nutritional and food needs. In order to meet the nutritional and food needs, it is important to produce agricultural products with low cost and high quality and efficiency. In the production of agricultural products, losses of up to 65% may occur in products due to some pests and diseases. For this reason, producers use different methods to increase the yield in agricultural areas and to prolong the durability of foodstuffs. One of these methods is the chemical control method, which is carried out under the name of agricultural control, which increases product productivity in the agricultural field. In fact, the basis of this method is the use of pesticides. In the global pesticides market, herbicides rank first among pesticides with a share of 47%. This is followed by insecticides (29%), fungicides (19%) and other pesticides (5%). In Turkey, insecticides (47%) take the first place in the use of pesticides, which is followed by herbicides (24%), fungicides (16%) and other pesticides (13%) [1, 2].

Pesticides, which are chemical and biological substances used in the fight against pests, are widely used for protective purposes against internal and external parasites in veterinary medicine and agricultural control. Pesticides are substances that are frequently used to obtain more products in the control of insects that damage agricultural products and various vectors that are the cause of disease [3, 4].

Pesticides are widely used in the field of agriculture to control pests. In addition to agricultural purposes, pesticides are also utilized in the fight against mosquitoes and weeds in houses, gardens and rural areas. However, pesticides which remain the same in the soil for a long-time cause water, soil and air pollution and ruin the ecological balance. The most important harmful effects of pesticides are that they enter the body through the food chain and cause acute and chronic poisoning in humans and animals. In addition, it has been reported that pesticide degradation products cause damage to biological systems as a result of accumulation in tissues and organs over time [5–7].

Pesticides are classified in different ways according to their formulation forms, the chemical structure of their active substances and the pest group they are used in. The most widely used classification is the classification made based on the pest group they are used in. Insecticide (insecticide), fungicide (fungicide), herbicide (weed killer), acaricide (spider killer), bactericide (bactericide), rodenticide (rodenticide), nematocide (nematode killer), aphicide (aphid killer), and algicide (algae killer) can be given as examples to the pesticides in this classification. Among them, herbicides, insecticides, and fungicides are the most widely used and studied in the world [8, 9].

Knowing the types of insecticides, their chemical structures, and their harmful effects on the environment and living things will guide the studies that can prevent the damage of these substances. This study, presented in line with this information, it is aimed to explain the biochemical and histopathological effects of insecticides on the organism by considering them with current articles.

## **2. Classification of insecticides**

Insects are one of the factors that threaten our health in the environments we live in. In addition to its psychological effects such as disgust in humans, it leads to the spreading of diseases such as plague, jaundice, and typhoid. Apart from these,

*An Overview of the Biochemical and Histopathological Effects of Insecticides DOI: http://dx.doi.org/10.5772/intechopen.100401*

insect bites can cause complaints such as itching, skin peeling, and pain in humans. Pesticides used to kill insects in many living areas such as agriculture, livestock farming, houses and workplaces are called as 'insecticide'. Insecticides are the second most widely used pesticide type in the world after herbicides [1, 9]. Insecticides are generally classified as in **Figure 1** [10].
